Kingston Technology KND2415TX manual Appendix D Commonly Asked Questions, What is Category 5?

Appendix D Commonly Asked Questions	15
Appendix D Commonly Asked Questions

Class J vs. Class JJ 100BASE-TX Fast Ethernet Repeaters

There are currently two classes of Fast Ethernet repeaters, dened as Class J and Class JJ .

Class J : in a maximum length segment topology, only one Class J repeater may exist between any two nodes within a single collision domain.

Class JJ : in a maximum length segment topology, two Class JJ repeaters may exist between any two nodes within a single collision domain.

Will 100BASE-TX run on Category 3 cable?

No! Category 3 (CAT 3) cabling even in short lengths generates too much near end crosstalk for 100BASE-TX networks. The IEEE 802.3u 100BASE-TX Fast Ethernet standard requires Category 5 100 W UTP or 100 W STP which complies with ISO/IEC 11801:1995.

What is Category 5?

Category 5 (CAT 5) is a further extension of the EIA/TIA-568 cabling system to 100 MHz. Category 5 components (i.e., UTP trunk and patch cables, modular plug, and patch panel, etc.) are dened by EIA/TIA-568, but with the characterizations extended to 100 MHz by TSB-36 and TSB-40. The cable grades are categorized as follows:

•Category 3: up to 16 MHz

•Category 4: up to 20 MHz.

•Category 5: up to 100 MHz.

Category 5 Compliance vs. Category 5 Performance?

Having CAT 5 components in your network installation does not necessarily achieve full Category 5 performance. To achieve any category-rated performance, make sure all cabling components are at least of the minimum category required.

To achieve full CAT 5 performance, all components must be CAT 5 compliant and terminated properly according to EIA/TIA-568 TSB-36 and TSB-40 guidelines.

KND2415TX Users Guide - Rev. A00 Kingston Technology Company